Surveillance, also presented sometimes to the user as Telemetry, Analytics or Targeted Advertising - is a feature of collecting personal information, or information about the use of the software by the company that provided the software. Or sometimes even, by a third party like Google Analytics or ID.me. The company may try to justify such a malicious behavior by pointing the user on the immediate benefits of the surveillance. Like: "You will get ads specifically chosen for you". This is just a tactic to ease the fact that you are being watched. More about surveillance you can see on <a href="https://www.gnu.org/proprietary/proprietary-surveillance.html">GNU.ORG/MALWARE</a>.
